docs: def validate_utterance(self, utterance):
          """
          Validate the given utterance and return a list of segments (start, end, label-value),
          that are outside of the utterance.
          """
          overflow_segments = []
  
          if self.label_list_idx in utterance.label_lists.keys():
              ll = utterance.label_lists[self.label_list_idx]
              start = 0
              end = utterance.duration
  
              for label in ll:
                  if start - label.start > self.threshold:
                      label_end = label.end if label.end != float('inf') else end
                      overflow_end = min(start, label_end)
                      overflow_segments.append((label.start, overflow_end, label.value))
  
                  if label.end != float('inf') and label.end - end > self.threshold:
                      overflow_start = max(end, label.start)
                      overflow_segments.append((overflow_start, label.end, label.value))
  
          return overflow_segments